Open my visualForce page when user clicks on a custom button in a related list using salesforce

i am stuck on a issue.hope somebody can guide me.

I have created a Custom Object named Hello.

i have added 2 fields in it named Lead & Accounts.and they both are lookups.

Now i can see related list of my object under Accounts and leads as well

I wanna add a custom button to this related list that should open any other custom visual force page.

Now when i reached here:

Name>> Setup>> Create>>Objects>>Hello>>Custom buttons & links.

I created a new button.

Inside this i clicked "List Button"

I found an option "Display in existing window using SideBar"

I also chose Content Source as VisualForcePage.

but

there is nothing in the Content Dropdown.

How i created the开发者_如何学编程 page

Name>> Setup>> Develop >>Pages>>new>>MyNewPage


<apex:page standardController="Hello__c" extensions="MyExtentionFile">

</apex:page>

I tried many combinations of Standard and custom controllers but could not get success. hope somebody can help me.

I followed this link : http://www.salesforce.com/us/developer/docs/pages/Content/pages_controller_sosc_custom_button.htm

If you're creating a list button you'll also need to set the recordSetVar for it to show up as a potential content source for Hello__c. You can see this in action in the doc link from your question.

<apex:page standardController="Hello__c" recordSetVar="hellos" extensions="MyExtensionFile">
  ... more code here ...
</apex:page>

First, Ralph gave you the right answer.

Check to see how you named your "Plural" form of your custom object Hello__c. If you accepted the defaults, you would have:

• Name: Hello
• Label: Hellos
• Object Name: Hello
• API Name: Hello_c (or namespaceprefix_Hello__c)

Then with the following page and class, Content Source as VisualForcePage will display it as selectable:

Class:

public with sharing class Hello_Controller 
{
    public Hello_Controller(ApexPages.StandardSetController controller) 
    {
        controller.setPageSize(10);
    }
}

Page:

<apex:page standardController="Hello__c" recordSetVar="Hellos" extensions="Hello_Controller">
</apex:page>